Why do sitcoms have laugh tracks?

Why exactly do TV sitcoms have recorded laughing--to remind us to laugh or what?

— Chris Hill

I realize this doesn't say much for TV viewers, but the answer to your question essentially is yes--the purpose of a laugh track is to tell the audience when it's time to laugh.

For those who've spent the last 55 years in a monastery, a laugh track is a pre-recorded effect inserted into most sitcoms not taped in front of a live audience. The laugh track is generally added in post-production--that is, during editing after the show is taped.

TV laugh tracks were first used on the "Hank McCune Show" back in 1950. Mr. McCune apparently wasn't getting many laughs, so engineers dubbed in recorded laughter. Sadly, the show lasted only three years and doesn't appear to be available on video, so we'll never know how truly funny it wasn't.

The man who made canned laughter what it is today was Charley Douglass, a sound engineer who devised the Laff Box. This was a contraption that stood a little over two feet tall and could be played like an organ to replicate different kinds of laughter, from guffaws to belly laughs. The operator could also select particular genders and ages, so a kids' show could have a simulated audience full of giggling children. No one's really sure where the original recordings came from; some say Douglass recorded audiences from "I Love Lucy," "The Red Skelton Show," or Marcel Marceau's mime act. All of these were heavy on sight gags, which probably made the recording process a little easier. Douglass, who died in 2003, won a special Emmy for engineering in 1992.

Today, of course, it's easy to insert any sound you want into a soundtrack. Most effects can be added and manipulated digitally. Douglass's company now produces a machine about the size of a laptop that will do basically the same thing as the old Laff Box, but more so. In addition to age and gender, it offers laughter in a number of accents, useful for shows done in other languages. Modern software makes it easy to add and manipulate sound effects. In fact, I'm writing this article on a computer that has a program called Adobe Audition that lets me add or delete sounds, change pitch or volume on specific sounds, and add effects like reverb or delay. I can take one or two voices and make it sound like an audience of hundreds.

The reason laugh tracks exist is to tell the audience when to laugh. Seriously. It's not that people don't get the jokes; rather, laugh tracks acknowledge the fact that laughter begets laughter. In a live audience people rely on cues from their neighbors to tell them when something is funny. The TV audience doesn't have those cues, so the laugh track provides them. Sitcoms aren't the only occasion when cues come in handy. For example, if you're reading the paper while you've got the game on TV, you'll likely look up at the screen if the crowd cheers or boos. The change in crowd noise signals to you that something significant just happened, and you might want to pay attention to find out what. Similarly, a laugh track tells you that something funny is going on. But a laugh track does more than indicate LAUGH NOW. It creates a mood and makes the audience more receptive. You see something along the same lines on late-night talk shows or for that matter at comedy clubs, where the host or another comedian comes out and tells jokes beforehand to warm up the audience.

Now that we know why laugh tracks work, we must ask ourselves, "Why a machine? Can't a live audience provide laughter?" Sure, and shows taped before an audience often use the audience's laughter. But a live audience is limiting--you can't do location shots, all the sets need to be on one sound stage, retakes are problematic, etc. Substituting a laugh track for a live audience simplifies matters, the obvious drawback being that the lack of feedback lets TV execs kid themselves that a show is funny when it's not.

Staff Reports are written by the Straight Dope Science Advisory Board, Cecil's online auxiliary. Though the SDSAB does its best, these columns are edited by Ed Zotti, not Cecil, so accuracywise you'd better keep your fingers crossed.